Check gauge for swaged fitting and tube connections

ABSTRACT

A check gauge for determining the acceptability of a swaged connection between a fitting and a tube where the fitting is swaged down over the tube and the tube must have a predetermined depth of penetration into the fitting.

United States Patent Dawson Oct. 2, 1973 CHECK GAUGE FOR SWAGED FITTINGAND TUBE CONNECTIONS James A. Dawson, Hazelwood, Mo.

McDonnell Douglas Corporation, St. Louis, Mo.

Filed: June 21, 1971 Appl. No.: 155,077

Inventor:

Assignee:

U.S. C1 33/174 G, 33/174 N, 285/93, 285/3822 Int. Cl. G0lb 5/14, GOlb5/20 Field of Search 33/174 G, 174 H, 33/174 K, 174 N, 168 R, 178 BReferences Cited UNITED STATES PATENTS Judge 33/168 R 2,585,521 2/1952Wandrus .13/174 (i Primary Examiner-Stanley N. Gilreath AssistantExaminer-J0n W. Henry Attorney-Gravely, Lieder & Woodruff 57 ABSTRACT Acheck gauge for determining the acceptability of a swaged connectionbetween a fitting and a tube where the fitting is swaged down over thetube and the tube must have a predetermined depth of penetration intothe fitting.

6 Claims, 7 Drawing Figures CHECK GAUGE FOR SWAGED FITTING AND TUBECONNECTIONS BRIEF BACKGROUND OF THE INVENTION The use of swagedconnections between tubes and fittings requires a predetermined lengthof grip on the tube by the fitting and a predetermined grip on the tubeby reduction of the fitting circumferentially about the tube. There are,thus, several critical dimensions for the connections of this character,and the present gauge quite simply and easily effects the accuratechecking of these dimensions in a handy and inexpensive tool.

The gauge herein disclosed is adapted to be used for approving orrejecting fitting-to-tube connections made by the swaging tool disclosedin my U.S. Pat. application, Ser. No. 28,578, filed Apr. 15, 1970, andit is useful with connections of the character shown in my U.S. Pat. No.3,572,779 issued Mar. 30, 1971. After a joint has been swaged with thetool of said application it is inspected with the gauge of thisinvention to determine the physical results. This is followed bypressure checks as normally required. The gauge must fit on the fittingand the depth of tube insertion is simultaneously checked by means ofthe gauge extension or finger. When these checks are made the gaugeshows that the swage diameter reduction is correct, that the length ofthe swage reaction is correct and that the tube insertion into thefitting is also correct. Thus, the gauge rapidly and visually checks theseveral characteristics of the swaging operation, requiresa minimum oftraining and reduces failures in tubing systems employing swaged joints.1 I

The gauge hereinafter described has the advantages of simultaneouslychecking the critical assembly dimensions for swaged fittings. It isespecially unique as it eliminates the need to take measurements withscales, calipers or micrometers. The gauge itself has a cylindrical orU-shaped body which fits over the swaged fitting or sleeve to show thatthese parts have been properly swaged, and it has an extenison or fingerwhich lies along the tube to check tube insertion in conjunction with amarking band previously imprinted or applied to the tube. The band ismade to have a width which establishes the insertion tolerancespermitted.

DESCRIPTION OF THE DRAWINGS The presently preferred forms of gauge areillustrated in the accompanying drawings, wherein:

FIG. 1 is a fragmentary longitudinal sectional view of a swaged fittingand tube connection having two swaged diameters and showing a gauge forchecking such a connection;

FIG. 2 is a sectional view of the gauge as applied to the connection,the view being taken at line 2-2 in FIG. 1;

FIG. 3 is a perspective view of the gauge itself for use with swagefitting connections of the type seen in FIG. 1;

FIG. 4 is an end view of the gauge of FIG. 3;

FIG. 5 is a side view of the gauge of FIG. 3;

FIG. 6 is a fragmentary longitudinal sectional view of a single diameterfitting and tube connection with a modified type of gauge for checkingthe connection; and

FIG. 7 is a side view of a swaging tool to show the tube with themarking band located in its desired position prior to the swagingoperation of the tool.

DETAILED DESCRIPTION OF THE EMBODIMENTS In Flg. l the swaged fitting andtube connection shows a fitting 10 having a flanged body portion 1 l andsleeves l2 and 13 extending axially in opposite directions from the body11. The sleeve 12 is seen prior to swaging in the form where theinternal surface 14 is cylindrical so as to receive the end portion oftube 15. the exterior of the sleeve 12 is formed with a plurality ofcircumferential enlargements l6, l7 and 18 which when swaged are pressedinwardly to imprint and grip the tube 15. At the right side of thefitting body the sleeve 13 is shown after being swaged such that twodifferent cylindrical diameters are formed at 19 and 20. Comparing theleft sleeve 12 with the right sleeve 13 it is observed that at the rightsleeve 13 the circumferencial enlargements 17 and 18 have beentransposed to the inside to deform and grip the innermost end 21 of thetube 22. this deformation by swaging leaves the exterior of the sleeve13 with a first cylindrical diameter surface 23. The outer end of sleeve13 is swaged to a smaller diameter at cylindrical surface 24 bytransposing the circumferential englargement 16 into the tube wall.

The gauge 25 for checking the swaged connection of FIG. 1 may be seen inFIGS. 2, 3 and 4 and 5. The gauge 25 has a body 26 of U-shape such thata first larger cylindrical surface 27 is formed to fit over the surface19 of the fitting of FIG. 1, and a smaller cylindrical surface 28 isformed to fit over the sleeve surface 20 of the fitting 10 in FIG. 1. Asviewed in FIGS. 2 or 4, the U-shaped gauging means, in order to slideonto the body of the swaged fitting must have the surfaces at theopening parallel so that the gauge will fit the diameter which is thedimension to check. The gauge body 26 is also provided with an extensionor finger 29 attached by a web 30 left after forming the slot 31 betweenthe surface 28 and the surface 32 of finger 29. The cylindrical surfaces27 and 28 are made just large enough to demonstrate adequacy ofreduction in diameter of the swaged fitting surfaces 19 and 20respectively.

The tube 22 prior to being inserted in the fitting sleeve 13 is markedwith a band 33 having a width T to denote the range of tolerance desiredfor proper tube insertion. After marking the tube 22 with the band 33,it is inserted in sleeve 13 and the sleeve is swaged as shown.

The swaged fitting and tube are checked with the gauge 25 by slippingthe body 26 over the sleeve 13 so that gauge surface 27 mates with thesleeve surface 19 and surface 28 mates with the sleeve surface 20. Thegauge body 26 is moved axially toward the fitting body 11 until it isstopped by a reference surface on the shoulder 34 of the inner end offinger extension 29 abutting the open end of sleeve 13, since thesurface 32 of this finger (FIGS. 4 and 5) is smaller in diameter thanthe adjacent surface 28. With the reference surface of shoulder 34 inabutment with the end of sleeve 13, the finger extension extends towardthe marking band 33. If the outer end of the finger lies anywhere on theband 33 it is visually determined that the tube 22 is properly inserted.The body 26 of the gauge, when fitted over the swaged sleeve 13 with thereference surface of shoulder 34 in abutment with the end of sleeve 13,determines the correct diameter A and swaged length of sleeve surface 19by the gauge surface 27, and surface 28 determines the correct diameterB of sleeve surface 20. In this manner the gauge 25 checks the threecritical factors, namely swage diameter, swage length, and tubeinsertion depth, which make an acceptable joint between the sleeve 13and the tube 22. This checking is accomplished in one operation ofplacing the gauge 25 in the position seen in FIG. 1. Should the U-shapedor semi-cylindrical surfaces 27 and 28,, or either of them, not fit overthe surfaces 19 or 20 of the sleeve 13, the swaging operation isdetermined to be faulty, and the joint is also found to be faulty if theouter end of the finger extension 29 does not reach the marking band 33or it if goes beyond this band. The marking band may have a width ofabout 0.30 inches to allow some variation in tube insertion depth andelongation of the sleeve 13 due to the swaging operation.

In FIG. 6 the modified gauge 35 is used to check a fitting A having asleeve 13A swaged to but a single diameter A for its finished outersurface. The gauge 35 is similar to that seen in FIG. 3, except its body26A is formed with one U-shaped or semi-cylindrical surface 27A. Thefinger extension 29A is provided with a shoulder 34A at the slot 31A,for the purpose of locating the gauge 35 against the outer end of theswaged sleeve 13A including a reference surface which abuts the open endof sleeve 13A, and fixing the location of the outer end of the gaugefinger extension 29A for determining if the finger end touches themarking band 33A on the tube 22A. In the view of FIG. 6, the end of thefinger 29A just reaches to the near edge of the band 33A to indicatethat the tube has been inserted the minimum acceptable distance.

In FIG. 7 there is seen a swaging tool 36 of the connector disclosed inapplication Ser. No. 28,578. The fitting of FIG. 1 is located in thetool 36 between the swaging jaws, and the tube 22 to be connectedthereto is inserted into the fitting until the prelocated marking band33 is lined up with the outer face of the moving jaw 37. The swagingoperation is performed and after the tool 36 has been removed the gaugeis applied as heretofore described to check the accuracy of the result.

The foregoing description refers to alternate embodiments of a gauge fordetermining the correct or incorrect swaging and tube insertioncharacteristics for swaged tube fittings. The U-shaped orsemi-cylindrical surfaces (FIG. 3) or the single surface 27A (FIG. 6),are adapted to slip over the swaged sleeve of a fitting to check thecompleteness of the swage. Over-swaging is not encountered since thetools have positive dieclosure stops, but insufficient swage reductionadversely affects the grip on the tube. Therefore, when the U-shapedsurface slips over the fitting sleeve it indicates sufficient swagereduction. In either gauge, the finger extension shoulder locates thegauge for checking the length of swage and the amount of insertion ofthe tube end in the sleeve of the fitting to assure the obtaining ofsufficient grip on the tube.

What is claimed is:

l. A gauge device for use with a swaged fitting having a body with anopen ended sleeve to receive a tube to be connected into the sleeve byswaging and in which the tube has a depth of penetration markingthereon; said gauge device including a body having a reference surfacethereon, a first surface at one side of said reference surface sized toreceive said body sleeve when properly swaged in diameter and length,and said body having a second surface located on the opposite side ofsaid reference surface from said first surface, said second surfacecooperating with the tube marking to indicate proper tube penetrationinto the fitting sleeve, said reference surface abutting the open end ofthe sleeve to position said first and second surfaces in gaugingrelation 0n the sleeve and tube.

2. The gauge of claim 1 wherein said first surface is semi-cylindricalto form a seat received over the fitting sleeve when properly swaged,and said second surface extends axially away from the cylindrical seatand outwardly toward the tube marking to visually show the extent oftube penetration into the sleeve.

3. The gauge of claim 1 wherein said first and second surfaces areoff-set with said second surface set inwardly of said first surface toexpose said reference surface to said first surface.

4. In a tube fitting gauge for use with swaged connections between apre-marked tube and a fitting having an open ended tube receiving sleeveadapted to be swaged onto the tube with consequent reduction indiameter; said gauge comprising a body having a main portion formed witha U-shaped recess adapted to receive the fitting sleeve when swaged toan acceptable length and diameter, said gauge body having an extensionportion directed to lie alongside the tube beyond the sleeve afterswaging, the position of said marking on the tube relative to the end ofsaid extension portion visually indicating the depth of insertion of thetube into the fitting sleeve, and said body having a reference surfaceon said extension portion adjacent said main portion to abut the openend of the tube receiving sleeve and locate the gauge in gaugingposition.

5. The gauge of claim 4 in which said extension portion has a shoulderadjacent said U-shaped recess, and said shoulder forming said referencesurface for locating said gauge body on said fitting by engaging the endof the tube receiving sleeve.

6. A gauge device for visually checking the sufficiency of a swagedconnection formed by fitting an open end sleeve over a tube having anindex mark thereon for indicating the depth of tube insertion into thesleeve and then swaging the sleeve over the tube, said gauge devicecomprising a body having a first gauge portion formed with parallelgauging surfaces spaced apart a distance equal to a desired diameter ofthe sleeve after swaging,- said body having a second gauge portionextending from said first gauge portion a length equal to a desiredposition of the index mark on the tube relative to the open end of thesleeve, and said body having a reference surface between said first andsecond gauge portions, said reference surface being located to engagethe sleeve end for positioning said second gauge portion along the tubetoward the location of the index mark, said reference surface engagementwith the sleeve end being indicative of said parallel surfaces of saidfirst portion receiving therebetween the sleeve after swaging.

k IF I JNITED STATES PATENT OFFICE CI EIRTIFIGATE OF CORRECTION DatedOctober 2, 1973 Patent No. 3,762,059

Inventor(s) James A. Dawson I It is certified that error appears in theabove-identified patent and that said Letters Patentere hereby correctedas shown below:-

In column 1, line 42, "extenison" should read "extension".

line 28, after "34A" insert a reference surface which abuts of sleeve13A"..,

Q In column 3, including the open end In column 3, lines 30 an d B lQ'after Y'lBA"; delete -'.including a reference surface which abuts ,7the open end of sleeve 13A.

Signed and sealed this 22nd day of January 197L (SEAL) Attest! RENE D.TEGTMEYER EDWARD M.FLETCHER ,JR.

Acting Commissioner of Patents Attesting Officer ORM P0-1050 (10-69)USCOMM-DC UOEHO-PGQ

1. A gauge device for use with a swaged fitting having a body with anopen ended sleeve to receive a tube to be connected into the sleeve byswaging and in which the tube has a depth of penetration markingthereon; said gauge device including a body having a reference surfacethereon, a first surface at one side of said reference surface sized toreceive said body sleeve when properly swaged in diameter and length,and said body having a second surface located on the opposite side ofsaid reference surface from said first surface, said second surfacecooperating with the tube marking to indicate proper tube penetrationinto the fitting sleeve, said reference surface abutting the open end ofthe sleeve to position said first and second surfaces in gaugingrelation on the sleeve and tube.
 2. The gauge of claim 1 wherein saidfirst surface is semi-cylindrical to form a seat received over thefitting sleeve when properly swaged, and said second surface extendsaxially away from the cylindrical seat and outwardly toward the tubemarking to visually show the extent of tube penetration into the sleeve.3. The gauge of claim 1 wherein said first and second surfaces areoff-set with said second surface set inwardly of said first surface toexpose said reference surface to said first surface.
 4. In a tubefitting gauge for use with swaged connections between a pre-marked tubeand a fitting having an open ended tube receiving sleeve adapted to beswaged onto the Tube with consequent reduction in diameter; said gaugecomprising a body having a main portion formed with a U-shaped recessadapted to receive the fitting sleeve when swaged to an acceptablelength and diameter, said gauge body having an extension portiondirected to lie alongside the tube beyond the sleeve after swaging, theposition of said marking on the tube relative to the end of saidextension portion visually indicating the depth of insertion of the tubeinto the fitting sleeve, and said body having a reference surface onsaid extension portion adjacent said main portion to abut the open endof the tube receiving sleeve and locate the gauge in gauging position.5. The gauge of claim 4 in which said extension portion has a shoulderadjacent said U-shaped recess, and said shoulder forming said referencesurface for locating said gauge body on said fitting by engaging the endof the tube receiving sleeve.
 6. A gauge device for visually checkingthe sufficiency of a swaged connection formed by fitting an open endsleeve over a tube having an index mark thereon for indicating the depthof tube insertion into the sleeve and then swaging the sleeve over thetube, said gauge device comprising a body having a first gauge portionformed with parallel gauging surfaces spaced apart a distance equal to adesired diameter of the sleeve after swaging, said body having a secondgauge portion extending from said first gauge portion a length equal toa desired position of the index mark on the tube relative to the openend of the sleeve, and said body having a reference surface between saidfirst and second gauge portions, said reference surface being located toengage the sleeve end for positioning said second gauge portion alongthe tube toward the location of the index mark, said reference surfaceengagement with the sleeve end being indicative of said parallelsurfaces of said first portion receiving therebetween the sleeve afterswaging.